()8 THE CANADIAN ENTOMOLOGIST. 



having the terminal joint nearly as long as the second {Catocald). Some- 

 times, as in Plusiodonta and in some spe nes of Phisia, the terminal joint 

 is exaggerated, reaching far above the head. In some genera they are 

 oblique and heavily fringed beneath, broadening toward the tip {Basi/odes) ; 

 then again they project forward horizontally, sometimes, in conjunction 

 with the pointed frontal tuft, forming a snout {Scolecocampd). In Her- 

 mmia, Hypena and some others, the second joint is disproportionately 

 long and fringed above with upright scales or hair, while the terminal joint 

 is short and slender. Sometimes they are curved upward, sickle-shaped, 

 nearly reaching the base of the thorax and closely scaled. Mere differ- 

 ences in the length of the palpi or in the proportions that their joints bear 

 to each other, do not authorize generic distinctions, if the general form 

 remain the same ; but insects having the palpi practically obsolete could 

 not be considered congeneric with those having them well developed ; 

 nor could an insect with porrect palpi be placed with one having elongate 

 horizontal palpi ; and this in turn could not be united with one in which 

 they were sickle-shaped and curved upward. Variations in the position 

 of the terminal joint, whether vertical, drooping or otherwise, do not 

 authorize a generic distinction. 



The antenncE. are very variable, but their variations do not afford good 

 generic characters, as they are generally sexual. Usually they are simple 

 in the % and more or less pectinate or ciliate in the ^ ; sometimes they 

 are both simple, and then again both sexes have them pectinated. In some 

 of the lower forms the males have them bunched or knotted at or below . 

 the middle, sometimes there is a tuft of hair at this point, and sometimes 

 alone, or in addition to either or both of these distinctions, there is a 

 decided bend, usually above the middle. Sexual characters alone should 

 not authorize genera, and therefore the variations of the antennae should 

 not have a generic value. 



The clothing of the head varies with the clothing of the entire insect, 

 but it is sometimes modified into tufts. There is occasionally a small tuft at 

 the base of the antennae, and often one in front, between the palpi. 

 Sometimes the clothing of the front is smooth and even ; then again it is 

 rough, divergent, occasionally mixed with bristles. None of these modi- 

 fications alone have a generic value, but they add to the value of others, 

 and combined with them, may attain a greater value. 



The size of the head as a whole, varies somewhat in the sexes, and 

 does not alone afford good generic characters, but combined with the 



